The present invention relates to certain 5-carboxanilido-2,4-bis-trifluoromethylthiazoles and their use for controlling rice blast.
U.S. Pat. No. 5,045,554 discloses a class of substituted 5-carboxanilido-thiazoles useful for control of plant fungus disease such as, for example Basidiomycetes such as Rhizoctonia, Sclerotium, and Corticium, as well as Alternaria and Spirothica, when applied to the growing plant, preferably as a foliar spray. Such 5-carboxanilidothiazoles are not known to have significant activity against the organism causing rice blast (Pyricularia oryzae). We have discovered that certain of these 5-carboxanilidothiazoles, specifically those in which the thiazole ring is substituted with trifluoromethyl groups at the 2 and 4 positions, are surprisingly effective for control of rice blast. In addition, these compounds provide improved activity against a variety of other fungi when compared with similar compounds which do not contain the bis-trifluoromethyl substituted thiazole entity.
The present invention provides compounds of Formula I: 
and salts thereof;
wherein: each R is independently halo (preferably chloro, bromo, or iodo), halo(C1-C5)alkyl (preferably halo(C1-C2)alkyl, more preferably perhalomethyl, most preferably trifluoromethyl), halo(C1-C5)alkoxy (preferably halo(C1-C2)alkoxy, more preferably perhalomethoxy, most preferably trifluoromethoxy), nitro, cyano, pentahalosulfur (preferably pentafluorosulfur), halomethylthio, haloethylthio, (C1-C2)alkylsulfinyl, halo(C1-C2)alkylsulfinyl, (C1-C2)alkylsulfonyl, or halo(C1-C2)alkylsulfonyl; n is from two to five (preferably two to four, more preferably three to four, most preferably three). Salts of the compound of Formula I include salts of strong bases, preferably a salt from reaction with sodium or potassium hydroxide, diazabicycloundecene, or diazabicyclononane, more preferably a salt formed from reaction with sodium or potassium hydroxide. Preferably each R is independently halo, haloalkyl, or haloalkoxy. Preferably, at least one, more preferably at least two, of the R groups are located in the ortho and/or para positions. The compounds of this invention to not include compounds in which Rn has the following substituent patterns: 2,4,6-trichloro, 2,3,4,5,6-pentachloro, 2,4,6-tribromo, 2,3,4,5,6-pentafluoro, and 2,6-dibromo-4-trifluoromethoxy.
The term xe2x80x9ccarboxanilidoxe2x80x9d means C6H5xe2x80x94NHxe2x80x94COxe2x80x94. The term xe2x80x9calkylxe2x80x9d means straight or branched chain (C1-C5)alkyl, unless otherwise specified. The term xe2x80x9clipophilicxe2x80x9d means having an affinity for organic solvents rather than aqueous solvents. The term xe2x80x9cactive ingredientxe2x80x9d means a compound of Formula I and/or any other compound with pesticidal activity.
As used herein, all percentages are percent by weight, unless otherwise specified. All percentage ranges are inclusive and combinable. All ratios are by weight and all ratio ranges are inclusive and combinable.
A second embodiment of this invention provides compositions comprising one or more compounds of Formula I and an agronomically acceptable carrier. Another embodiment this invention provides a method to control fungal disease on a plant comprising applying to the plant, vegetative propagules of the plant including seeds and seedlings, the growing medium of the plant, or water around the plant foliage, a fungicidally effective amount of a composition comprising one or more compounds of Formula I, as described above.
The compounds and compositions of the present invention are particularly useful for the control of rice blast. However, they also control other phytopathogenic fungi on a wide variety of crops. The compositions may be applied as a seed protectant, as a seedling or seedling box treatment, as a foliar fungicide, as a soil fungicide, or as a combination thereof The quantity of the compound or composition required for control of a particular spectrum of fungi will depend upon the growth stage of the crop, the crop to be treated, the relative stage of infection by the fungi, the type and condition of soil, the amount of rainfall, and the specific compounds employed. Under some conditions the compounds or compositions of the invention may be incorporated into the soil or other growth medium prior to planting a crop. This incorporation may be by any convenient means, including mixing with the soil, applying the compositions to the surface of the soil and then discing or dragging into the soil to the desired depth, or by employing a liquid carrier. The compositions of this invention can be diluted or applied as is to plant foliage and/or soil as aqueous sprays by methods commonly employed, such as conventional high-volume hydraulic a sprays, low-volume sprays, air-blast, and aerial sprays. The dilution and rate of application will depend upon the type of equipment employed, the method and frequency of application desired, the fungicide application rate, and the fungi to be controlled. The compositions can be mixed with fertilizers or fertilizing materials before their application. The compositions can be utilized as the sole pesticidal agent or they can be employed in conjunction with other pesticidal agents such as, for example, microbicides, other fungicides, herbicides, insecticides, and acaricides.
In foliar applications an application rate of from 10 to 500 grams per hectare (xe2x80x9cg/haxe2x80x9d), preferably from 30 to 250 g/ha, is usually employed. In soil applications an application rate of from 10 to 1000 g/ha, preferably from 100 to 500 g/ha, is usually employed.
For such purposes these compounds can be used in the technical grade or pure form as prepared or, preferably, as formulated compositions. Solid compositions include, for example: wettable powders typically containing, for example, from 10 to 90%, preferably from 50 to 90% active ingredient, from 2 to 10% dispersing agents, up to 10% stabilizers and/or other additives such as penetrants, stickers, and surfactants, and a solid inert carrier such as clay, silica, or natural or synthetic carrier; dusts which are usually formulated as a concentrate having a composition similar to a wettable powder but without dispersant and usually containing from 0.5 to 10% active ingredient; and granules containing, for example, from 0.01 to 80% active ingredient and 0 to 10% additives such as stabilizers, surfactants, slow release modifiers, and binding agents which are prepared by, for example, agglomeration or impregnation techniques and have a size greater than wettable powders and up to 1-2 millimeters. Liquid compositions include, for example, aqueous or solvent based solutions, emulsifiable concentrates, emulsions, suspension concentrates, and flowables which typically contain from 0.01 to 99.9% of the active ingredient, an agronomically acceptable carrier, and one or more adjuvants. More typically such liquid compositions will contain from 1.0 to 85% of the active ingredient.
As used herein, the term xe2x80x9cagronomically acceptable carrierxe2x80x9d means any material with which a compound of Formula I is formulated to facilitate application or to facilitate storage, transport, or handling of the compound of Formula I and which is not phytotoxic to plant foliage. A carrier may be a solid or liquid, including a material which is normally gaseous but which has been compressed to form a liquid. Any of the carriers typically useable in formulating fungicidal compositions may be used. Suitable solid carriers include, for example, natural and synthetic clays and silicates, salts such as calcium carbonate and ammonium sulfate, carbon-based materials such as charcoal and bitumen, sulfur, natural and synthetic resins, waxes, agar, fertilizers, cellulose-based materials such as sawdust and corn cobs, and mixtures thereof. Suitable liquid carriers include, for example, water, alcohols, ketones, ethers, aromatic and aliphatic hydrocarbons, petroleum fractions, chlorinated hydrocarbons, polar organic liquids, and mixtures thereof. Combinations of solid and liquid carriers may also be used.
It is usually desirable, particularly in the case of sprayable formulations, to include one or more adjuvants, such as wetting agents, spreading agents, dispersing agents, stickers, adhesives, emulsifying agents and the like in accordance with agricultural practices. Such adjuvants commonly used in the art can be found in McCutcheon""s Emulsifiers and Detergents, McCutcheon""s Emulsifiers and Detergents/Functional Materials, and McCutcheon""s Functional Materials all published annually by McCutcheon Division of MC Publishing Company (New Jersey) and Farm Chemicals Handbook published by Meister Publishing Company (Ohio).
The fungicidal compositions of this invention may also contain other ingredients, for example, further active compounds possessing herbicidal, insecticidal, or fungicidal properties, in accordance with the requirements of the locus to be treated and the treatment method.
Compounds of Formula I are prepared by standard procedures as disclosed in U.S. Pat. No. 5,045,554 (see particularly columns 4-15) by reacting a 2,4-bis-trifluoromethyl substituted thiazole having a 5-carbonylchloride substituent with an appropriately substituted aniline in suitable solvent(s) at an elevated temperatures. An example process is as follows: